NANOROBOTICS

DEFINITION:

Nanoroboticsis theemerging technologyfield of creating machines orrobotswhose components are at or close to the microscopic scale of ananometer(10−9meters).

More specifically, nanorobotics refers to thenanotechnologyengineering discipline of designing and buildingnanorobots, with devices ranging in size from 0.1-10 micrometers and constructed of nanoscale or molecular components.

The namesnanobots,nanoids,nanites,or nanomachineshave also been used to describe these devices currently under research and development.

  • Nanobotsare incredibly tinyrobots, down at a microscopic scale. The name comes from a combination of thenanometer, the scale the devices are built at, and robot.
  • Nanoids are minuscular nano rabots which can be used to doany variety of things right from cleaning your lungs to fixing the ozone layer.They are built using a Nano Assemblers and are in turn controlled by nano computers. You can imagine the complexity of implementation of the concept when it comes to machining those Nano Assemblers which will work any way you will program.
  • Ananiteis a microscopicroboticdevice and a form ofnanotechnology. A nanite is built by manipulatingatomsand containsgigabytesofcomputermemory. It is small enough to enter livingcellsand can be programmed to do numerous tasks. Nanites are used by theFederationfor medical purposes and are designed to work inside nucleii during cellular surgery. When they are not used, nanites are stored in a non-functional state. When necessary nanites can be destroyed with a burst of high-levelgamma radiation
  • Nanomachines are devices built from individual atoms. Some researchers believe that snanomachines will one day be able to enter living cells to fight disease. They also hope to one day build nanomachines that will be able to rearrange atoms in order to construct new objects. If they succeed, nanomachines could be used to literally turn dirt into food and perhaps eliminate poverty.

Different approaches:

  1. Biochip: The joint use ofnanoelectronics,photolithography, and newbiomaterialsprovides a possible approach to manufacturing nanorobots for common medical applications, such as for surgical instrumentation, diagnosis and drug delivery.
  2. Nucleic Acid Robots (Nubots): Nubot is an abbreviation for "nucleic acid robots". Nubots are synthetic robotics devices at the nanoscale. Representative nubots include the several DNA walkers reported by NadrianSeeman's group at NYU, Niles Pierce's group at Caltech, John Reif's group at Duke University, Chengde Mao's group at Purd
  3. Positional nanoassembly: developing positionally-controlled diamond mechanosynthesis capable of building diamondoid medical nanorobots.
  4. Bacteria based: This approach, like thebacteriumEscherichia coli.Thus the model uses a flagellum for propulsion purposes. The use of electromagnetic fields are normally applied to control the motion of this kind of biological integrated device, but has limited applications.

How nanorobot works…..??

There are three main considerations scientists need to focus on when looking at nanorobots moving through the body –

  • Navigation
  • power
  • Locomotion.

Nanotechnologists are looking at different options for each of these considerations, each of which has positive and negative aspects.

  • Navigation

Most options can be divided into one of two categories:

  1. external systems
  2. onboard systems.

External navigation systems might use a variety of different methods to pilot the nanorobot to the right location. One of these methods is to use ultrasonic signals to detect the nanorobot's location and direct it to the right destination. Doctors would beam ultrasonic signals into the patient's body. The signals would either pass through the body, reflect back to the source of the signals, or both. The nanorobot could emit pulses of ultrasonic signals, which doctors could detect using special equipment with ultrasonic sensors. Doctors could keep track of the nanorobot's location and maneuver it to the right part of the patient's body.

Using a Magnetic Resonance Imaging (MRI) device, doctors could locate and track a nanorobot by detecting its magnetic field. Doctors and engineers at the EcolePolytechnique de Montreal demonstrated how they could detect, track, control and even propel a nanorobot using MRI. They tested their findings by maneuvering a small magnetic particle through a pig's arteries using specialized software on an MRI machine. Because many hospitals have MRI machines, this might become the industry standard -- hospitals won't have to invest in expensive, unproven technologies.

Doctors might also track nanorobots by injecting a radioactive dye into the patient's bloodstream. They would then use a fluoroscope or similar device to detect the radioactive dye as it moves through the circulatory system. Complex three-dimensional images would indicate where the nanorobot is located. Alternatively, the nanorobot could emit the radioactive dye, creating a pathway behind it as it moves through the body.

Other methods of detecting the nanorobot include using X-rays, radio waves, microwaves or heat. Right now, our technology using these methods on nano-sized objects is limited, so it's much more likely that future systems will rely more on other methods.

Onboard systems, or internal sensors, might also play a large role in navigation. A nanorobot with chemical sensors could detect and follow the trail of specific chemicals to reach the right location. A spectroscopic sensor would allow the nanorobot to take samples of surrounding tissue, analyze them and follow a path of the right combination of chemicals.

Hard as it may be to imagine, nanorobots might include a miniature televisioncamera. An operator at a console will be able to steer the device while watching a live video feed, navigating it through the body manually. Camera systems are fairly complex, so it might be a few years before nanotechnologists can create a reliable system that can fit inside a tiny robot.

External systems that don't use tethers could rely on microwaves, ultrasonic signals ormagneticfields. Microwaves are the least likely, since beaming them into a patient would result in damaged tissue, since the patient's body would absorb most of the microwaves and heat up as a result. A nanorobot with a piezoelectric membrane could pick up ultrasonic signals and convert them into electricity. Systems using magnetic fields, like the one doctors are experimenting with in Montreal, can either manipulate the nanorobot directly or induce an electrical current in a closed conducting loop in the robot.

  • Power

Just like the navigation systems, nanotechnologists are considering both external and internal power sources. Some designs rely on the nanorobot using the patient's own body as a way of generating power. Other designs include a small power source on board therobotitself. Finally, some designs use forces outside the patient's body to power the robot.

Nanorobots could get power directly from thebloodstream. A nanorobot with mounted electrodes could form abatteryusing the electrolytes found in blood. Another option is to create chemical reactions with blood to burn it for energy. The nanorobot would hold a small supply of chemicals that would become a fuel source when combined with blood.

A nanorobot could use the patient's body heat to create power, but there would need to be a gradient of temperatures to manage it. Power generation would be a result of theSeebeck effect. The Seebeck effect occurs when two conductors made of different metals are joined at two points that are kept at two different temperatures. The metal conductors become a thermocouple, meaning that they generate voltage when the junctures are at different temperatures. Since it's difficult to rely on temperature gradients within the body, it's unlikely we'll see many nanorobots use body heat for power.

While it might be possible to create batteries small enough to fit inside a nanorobot, they aren't generally seen as a viable power source. The problem is that batteries supply a relatively small amount of power related to their size and weight, so a very small battery would only provide a fraction of the power a nanorobot would need. A more likely candidate is acapacitor, which has a slightly better power-to-weight ratio.

Another possibility for nanorobot power is to use anuclear powersource. The thought of a tiny robot powered by nuclear energy gives some people the willies, but keep in mind the amount of material is small and, according to some experts, easy to shield [source:Rubinstein]. Still, public opinions regarding nuclear power make this possibility unlikely at best.

External power sources include systems where the nanorobot is either tethered to the outside world or is controlled without a physical tether. Tethered systems would need a wire between the nanorobot and the power source. The wire would need to be strong, but it would also need to move effortlessly through the human body without causing damage. A physical tether could supply power either by electricity or optically. Optical systems uselightthroughfiber optics, which would then need to be converted intoelectricityon board the robot.

  • Locomotion.

Assuming the nanorobot isn't tethered or designed to float passively through thebloodstream, it will need a means of propulsion to get around the body. Because it may have to travel against the flow of blood, the propulsion system has to be relatively strong for its size. Another important consideration is the safety of the patient -- the system must be able to move the nanorobot around without causing damage to the host.

Some scientists are looking at the world of microscopic organisms for inspiration. Paramecium move through their environment using tiny tail-like limbs calledcilia. By vibrating the cilia, the paramecium can swim in any direction. Similar to cilia areflagella, which are longer tail structures. Organisms whip flagella around in different ways to move around.

Scientists inIsraelcreatedmicrorobot, a robot only a few millimeters in length, which uses small appendages to grip and crawl through blood vessels. The scientists manipulate the arms by creatingmagneticfields outside the patient's body. The magnetic fields cause therobot'sarms to vibrate, pushing it further through the blood vessels. The scientists point out that because all of the energy for the nanorobot comes from an external source, there's no need for an internal power source. They hope the relatively simple design will make it easy to build even smaller robots.

Other devices sound even more exotic. One would usecapacitorsto generate magnetic fields that would pull conductive fluids through one end of anelectromagneticpumpand shoot it out the back end. The nanorobot would move around like a jet airplane. Miniaturizedjet pumpscould even use blood plasma to push the nanorobot forward, though, unlike the electromagnetic pump, there would need to be moving parts.

Another potential way nanorobots could move around is by using a vibrating membrane. By alternately tightening and relaxing tension on a membrane, a nanorobot could generate small amounts of thrust. On the nanoscale, this thrust could be significant enough to act as a viable source of motion.

Teeny, Tiny Tools

Current microrobots are only a few millimeters long and about a millimeter in diameter. Compared to the nanoscale, that's enormous -- a nanometer is only one-billionth of a meter, while a millimeter is one-thousandth of a meter. Future nanorobots will be so small, you'll only be able to see them with the help of amicroscope. Nanorobot tools will need to be even smaller. Here are a few of the items you might find in a nanorobot's toolkit:

  • Medicine cavity-- a hollow section inside the nanorobot might hold small doses of medicine or chemicals. The robot could release medication directly to the site of injury or infection. Nanorobots could also carry the chemicals used in chemotherapy to treatcancerdirectly at the site. Although the amount of medication is relatively miniscule, applying it directly to the cancerous tissue may be more effective than traditional chemotherapy, which relies on the body's circulatory system to carry the chemicals throughout the patient's body.
  • Probes,knivesandchisels-- to remove blockages and plaque, a nanorobot will need something to grab and break down material. They might also need a device to crush clots into very small pieces. If a partial clot breaks free and enters thebloodstream, it may cause more problems further down the circulatory system.
  • Microwave emittersandultrasonic signal generators-- to destroy cancerous cells,doctorsneed methods that will kill a cell without rupturing it. A ruptured cancer cell might release chemicals that could cause the cancer to spread further. By using fine-tuned microwaves or ultrasonic signals, a nanorobot could break the chemical bonds in the cancerous cell, killing it without breaking the cell wall. Alternatively, the robot could emit microwaves or ultrasonic signals in order to heat the cancerous cell enough to destroy it.
  • Electrodes-- two electrodes protruding from the nanorobot could kill cancer cells by generating anelectriccurrent, heating the cell up until it dies.
  • Lasers-- tiny, powerful lasers could burn away harmful material like arterial plaque, cancerous cells or blood clots. The lasers would literally vaporize the tissue.

The two biggest challenges and concerns scientists have regarding these small tools are making them effective and making them safe. For instance, creating a small laser powerful enough to vaporize cancerous cells is a big challenge, but designing it so that the nanorobot doesn't harm surrounding healthy tissue makes the task even more difficult. While many scientific teams have developed nanorobots small enough to enter the bloodstream, that's only the first step to making nanorobots a real medical application.

Nanorobotic Technology:

Nanorobotic technology play vital role in medical industries. They make medical applications easy and effective. The nanorobot swims in the human blood for findinginformation, defects and also for delivering drugs. There are two necessary needs for using nanorobots. The first need is for surgery intervention and other need is to monitor patient’s body. For this purpose, the nanorobot requires specific controls, sensors and actuators. The sensors used in nanorobots have super sensitive, ultra fast and non-invasive.

Applications on Nano Robotics :

Nanorobots are used in medical industries for several purposes. They are:

  • Break kidney stones,
  • Repair injured tissues,
  • Blockage in coronary arteries cause heart attacks are cleared,
  • Clear spinal and back problems,
  • Used to find glucose demand in diabetes patient.
  • Space colonization efforts would use nanorobots to construct projects on other planets by remote control using the environmental materials at hand. Sensors and cameras would be built by the nanorobots, and used to monitor the construction projects.
    Plans for space elevators entail constructing a cable leading from earth to Earth's orbit using carbon nanotubes as the material. Electric lifts would then run the length of the cable. The lightweight durability of carbon nanotubes makes them a likely material for constructing the satellites and space stations that will ride the lift.
    Some of the uses based on environment are:
  • To purify oxygen and carbon dioxide,
  • To purify wastes in water,
  • To check diagnose and reorganize biological structures.

Advantages of Nanorobotics:

Some of the advantages of nanorobotics are:

  • Minimizes the risk,
  • Minimizes the cost of surgery,
  • Easy to operate,
  • Operations failures are eliminated.

Disadvantages of Nanorobotics:

Some of the disadvantages of nanorobotics are:

  • Cluster of different nanorobots with one another is harmful,
  • Installation cost is high,
  • Maintenance is difficult.
  • Chemist object that an assembler would need an 10 robotics “fingers” to carry out operations and that there isn’t room for them all.
  • This technology is still science fiction and an unfamiliar territory.

Conclusion:

The Nanorobotic future is very bright. Nowadays nanorobotics is developing faster day by day because of their use in medical industries. They cure many senior ill patients and renew their lives by the use of nanorobotics. HIV, cancer and other harmful diseases are also under progress for curing. The development of nanorobotics is endless and there is more advancement yet to come in future.